1. Field of the Invention
The present invention relates to an integrated gas distribution system for safely and reliably controlling the flow of gaseous fuel to gas appliances in a dwelling, such as a house.
2. Description of the Prior Art
Many houses today use natural gas as an energy source to fuel appliances such as stoves, ovens, dryers, furnaces, space heaters, and the like. Gas plumbing lines are used to supply gas from a service entrance, usually located outside the house, to each appliance. In a conventional gas house, the service entrance typically includes a manual shutoff valve and a pressure regulator which are required under national and local codes.
The gas distribution system in a typical house, however, cannot automatically monitor and control the flow of gaseous fuel to appliances in the house. Rather, gas fills the entire line leading to a gas point of attachment and is immediately made available to any appliance that is connected thereto. When the appliance is activated, gas flows unrestricted to the appliance regardless of whether it is in working order or of other conditions existing in the house itself.
Such a gas distribution system can create potentially serious safety hazards. One hazard involves unrestricted gas flow from the gas points of attachment. Typically, the appliances are threadably attached to a gas line. Therefore, should an appliance be disconnected without turning off the manual shutoff valve in the service entrance, gas will escape into the living space.
Another type of gas connection, found in foreign applications, employs a gas outlet having a manual valve in combination with an interlocking mechanism. The interlock prevents the valve from being activated and gas from flowing until the connector that supplies gas to the appliance has been plugged into the point of attachment. However, the interlock mechanism can be relatively easy to bypass, even by children, so that the valve can be opened manually when no appliance is connected to the attachment point, thus allowing gas to escape into the house and endangering lives and property.
Lack of a system for monitoring the flow of gas in a house creates other safety hazards. Gas leaks from the supply lines can go undetected, creating the possibility of a fire or explosion in the house.
If a gas leak does occur, it is desirable not only to sense that condition, but also, to take immediate, corrective action to avert potential disaster. Such action might include shutting down a particular gas line or the entire gas distribution system.
Conventional gas systems have no control system for automatically shutting off the gas supply in the event of an emergency, but rather, must rely on an occupant or the gas utility company to shut off the manual valve in the service entrance. By that time, however, it may be too late to avoid a disaster. Furthermore, having to rely on a manual valve for shutting down the gas supply is ineffective should a gas leak go undetected because the house is unoccupied.
Other conditions may exist in the house that require interrupting the supply of gas to appliances. For instance, should a fire break out in the house, less destruction will occur if the gaseous fuel supply to the entire house is shut off. However, during a fire or other emergency situation, there is often little opportunity to take such measures. Unfortunately, most houses are equipped solely with conventional gas/smoke detectors, which are stand-alone units capable of emitting only an audible alarm. Conventional gas systems lack the necessary monitor and control devices and communication networks for detecting emergency conditions in the house and taking the necessary corrective action in response to those conditions to minimize damage to the house and risk to the safety of its occupants.